Publications by authors named "Orstavik T"

We have previously demonstrated that the rat submandibular gland releases immunoreactive kallikrein into the circulation. To study the role of the autonomic nervous system in this release, submandibular gland blood flow and kallikrein concentration in peripheral arterial and venous blood from the gland were measured and secretion rates calculated before and after parasympathetic and sympathetic nerve stimulation (8V, 2 msec, 10 Hz) for 1 minute. Immunoreactive kallikrein in plasma was measured by radioimmunoassay, and timed collections of venous outflow were used to measure blood flow.

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An immunoradiometric assay has previously been developed for measurement of rat glandular kallikrein. In the present paper, further studies on the specificity and sensitivity of the method are described. Problems of interference of immunologically cross-reacting antigens were overcome by proper preabsorption of the antibody.

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The development of an excess antibody assay for rat glandular kallikrein is described. This assay permits immunological determination of kallikrein as well as a simultaneous specific measurement of kallikrein enzymatic activity. The assay is based on coupling of immunopurified anti-kallikrein immunoglobulin to a solid phase.

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The 4-methoxynaphthylamide (MNA) derivative of D-Val-Leu-Arg-4-MNA has been used as a substrate for the histochemical localization of esteroproteases in the submandibular gland of rats, and compared with the substrate alpha N-O-met. The hydrolysis of Val-Leu-Arg-4-MNA by esteroproteases was investigated using spectrophotometry and isoelectric focusing. Both methods demonstrated that the substrate is cleaved by different enzymes and is not a monospecific kallikrein marker, although Val-Leu-Arg-4-MNA had a much smaller spectrum of enzyme activities than alpha N-O-met.

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The unstimulated rat submandibular gland releases kallikrein into the circulation. This release is greatly increased by sympathetic nervous stimulation of the gland. We studied the effect of an angiotensin I converting enzyme (ACE) inhibitor (captopril) on blood flow of the unstimulated submandibular gland, and the effect of the ACE inhibitor on blood kinins and blood pressure of rats with prior sympathetic stimulation of the gland.

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Tonin and kallikrein are serine proteases present in high concentrations in the submandibular gland of the rat. These enzymes release the vasoactive peptides angiotensin II and lysyl-bradykinin from the precursors angiotensinogen and kininogen, respectively. Tonin and kallikrein were purified from homogenates of rat submandibular gland, and antisera against each protein were raised in rabbits.

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The subcellular localization of kallikrein was studied in the rat pancreas using the immunocytochemical protein A-gold technique. Kallikrein was found at the level of the rough endoplasmic reticulum (RER), Golgi cisternae, condensing vacuoles, and zymogen granules of the pancreatic acinar cells as well as in the acinar lumen. The effect of various tissue processings on the immunocytochemical labeling of kallikrein was evaluated using pancreatic tissue fixed in glutaraldehyde and embedded in Epon, Lowicryl K4M, or glycol methacrylate (GMA).

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The initial translation product of mouse submaxillary gland mRNA has a molecular weight of about 50,000. We have now translated renin mRNA in frog oocytes which are known to be able to remove the so-called "pre"- or "signal"- sequence from products of injected mRNAs. From these injected oocytes, we could precipitate with antirenin a 48,000 dalton polypeptide.

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The purpose of this study was to determine whether glandular kallikrein in rat pancreas is located in the beta cells of the endocrine pancreas or in the acinar cells of the exocrine pancreas. Kallikrein was measured by radial immunodiffusion and a direct radioimmunoassay in homogenates of pancreas obtained from 1) control rats, 2) rats with pancreatic beta cells selectively destroyed by streptozotocin, and 3) rats with acinar cell atrophy induced by pancreatic duct occlusion. Beta cell destruction was confirmed by the presence of hyperglycemia and by an almost total depletion of insulin-producing cells as demonstrated immunohistochemically.

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A one-step immunoadsorption method for the isolation of glandular kallikreins is described using the immunoglobulin fraction from rabbit anti-(rat glandular kallikrein) serum coupled to CNBr-activated Sepharose 4B. The adsorptions of 125I-labelled kallikrein or unlabelled kallifrein from 100 000 g submandibular gland supernatants were more than 97% complete. The elution of kallikrein from the immunoadsorbent using guanidine hydrochloride gave about 20% yield, which could be increased up to 70% by including 0.

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The transport of radiolabelled rat submandibular gland kallikrein was studied after local administration to the resting and activated rat submandibular gland. The iodinated kallikrein was electrophoretically, immunologically, and biologically indistinguishable from the intact enzyme. After intraductal and intraglandular application the radioactivity in venous effluent was quantitated and characterized.

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The localization of kallikrein in human exocrine organs was studied with a direct immunofluorescence method. In the submandibular and parotid salivary glands, kallikrein was found apically in the striated duct cells whereas it was absent from the main excretory ducts or present only as a weak luminal rim. Kallikrein was not found in the acinar cells or in cells of the intercalated ducts.

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1. The cellular localization of kallikrein was investigated in rat and human exocrine glands and kidney by a direct immunofluorescence technique. 2.

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Extractable kallikrein was quantitated in the submandibular, sublingual, and parotid glands and in the pancreas. No kallikrein was detected in the exorbital lacrimal glands and tears. The highest kallikrein concentrations (EU/ml) were in all major salivary gland secretions seen after alpha-adrenergic stimulation, less after beta-adrenergic and least after parasympathetic stimulation.

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Kallikrein was located by the direct immunofluorescence technique to the granule-containing luminal portion of pancreatic acinar cells. For the demonstration of the intracellular distribution of pancreas kallikrein, in vivo fixation of the gland was necessary. No kallikrein was found in the duct cells or in the islets of Langerhans.

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